/*
 * cuda_md5_kernel.c
 * contient le kernel a exécuter côté GPU pour le calcul de MD5
 * L'implémentation de référence du RFC 1321 a été sélectionnée et utilisée
 * avec quelques modifications pour le fonctionnement en 64 bits et parce
 * qu'elle utilisait des fonctions d'API non utilisable avec CUDA quelques
 * adaptations testées sur la suite de test du RFC
 * ***RSA Data Security, Inc. MD5 Message-Digest Algorithm***
 * @author fred
 */

#include "cuda_kernel_md5_include.h"

#define S11 7
#define S12 12
#define S13 17
#define S14 22
#define S21 5
#define S22 9
#define S23 14
#define S24 20
#define S31 4
#define S32 11
#define S33 16
#define S34 23
#define S41 6
#define S42 10
#define S43 15
#define S44 21

static __device__ void MD5Transform (UINT4 [4], unsigned char [64]);
static __device__ void Encode (unsigned char *, UINT4 *, unsigned int);
static __device__ void Decode (UINT4 *, unsigned char *, unsigned int);
static __device__ void MD5_memcpy (POINTER, POINTER, unsigned int);
static __device__ void MD5_memset (POINTER, int, unsigned int);

static __device__ unsigned char PADDING[64] = {
  0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

/* F, G, H and I are basic MD5 functions.
 */
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z)))

/* ROTATE_LEFT rotates x left n bits.
 */
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))

/* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
   Rotation is separate from addition to prevent recomputation.
*/
#define FF(a, b, c, d, x, s, ac) {			\
    (a) += F ((b), (c), (d)) + (x) + (UINT4)(ac);	\
    (a) = ROTATE_LEFT ((a), (s));			\
    (a) += (b);						\
  }
#define GG(a, b, c, d, x, s, ac) {			\
    (a) += G ((b), (c), (d)) + (x) + (UINT4)(ac);	\
    (a) = ROTATE_LEFT ((a), (s));			\
    (a) += (b);						\
  }
#define HH(a, b, c, d, x, s, ac) {			\
    (a) += H ((b), (c), (d)) + (x) + (UINT4)(ac);	\
    (a) = ROTATE_LEFT ((a), (s));			\
    (a) += (b);						\
  }
#define II(a, b, c, d, x, s, ac) {			\
    (a) += I ((b), (c), (d)) + (x) + (UINT4)(ac);	\
    (a) = ROTATE_LEFT ((a), (s));			\
    (a) += (b);						\
  }

/* MD5 initialization. Begins an MD5 operation, writing a new context.
 */
__device__ void MD5Init (MD5_CTX *context)
{
  DEBUG_PRINT(("<MD5Init>\n"));

  context->count[0] = context->count[1] = 0;
  /* Load magic initialization constants.
   */
  context->state[0] = 0x67452301;
  context->state[1] = 0xefcdab89;
  context->state[2] = 0x98badcfe;
  context->state[3] = 0x10325476;

  DEBUG_PRINT(("</MD5Init ends with state : %d %d %d %d>\n", context->state[0],
	       context->state[1], context->state[2], context->state[3]));
}

/* MD5 block update operation. Continues an MD5 message-digest
   operation, processing another message block, and updating the
   context.
*/
__device__ void MD5Update (MD5_CTX *context, 
			   unsigned char *input, 
			   unsigned int inputLen)
{
  unsigned int i, k, index, partLen;

  DEBUG_PRINT(("<MD5Udapte with input "));	
  for (k=0;k<inputLen;k++)
    DEBUG_PRINT(("%d-", input[k]));
  DEBUG_PRINT((">\n"));

  /* Compute number of bytes mod 64 */
  index = (unsigned int)((context->count[0] >> 3) & 0x3F);

  /* Update number of bits */
  if ((context->count[0] += ((UINT4)inputLen << 3))

      < ((UINT4)inputLen << 3))
    context->count[1]++;
  context->count[1] += ((UINT4)inputLen >> 29);

  DEBUG_PRINT(("<update makes : %d %d>\n", context->count[0], context->count[1]));
 
  partLen = 64 - index;

  /* Transform as many times as possible.
   */
  if (inputLen >= partLen) {
    MD5_memcpy
      ((POINTER)&context->buffer[index], (POINTER)input, partLen);

    MD5Transform (context->state, context->buffer);

    for (i = partLen; i + 63 < inputLen; i += 64)
      MD5Transform (context->state, &input[i]);

    index = 0;
  }
  else
    i = 0;

  /* Buffer remaining input */
  MD5_memcpy
    ((POINTER)&context->buffer[index], (POINTER)&input[i],
     inputLen-i);

  DEBUG_PRINT(("</MD5Udapte>\n"));
}

/* MD5 finalization. Ends an MD5 message-digest operation, writing the
   the message digest and zeroizing the context.
*/
//unsigned char digest[16];                         /* message digest */
//MD5_CTX *context;                                       /* context */
__device__ void MD5Final (unsigned char digest[16], MD5_CTX *context)
{
  unsigned char bits[8];
  unsigned int index, padLen;

  DEBUG_PRINT(("<MD5Final>\n"));

  /* Save number of bits */
  Encode (bits, context->count, 8);

  /* Pad out to 56 mod 64.
   */
  index = (unsigned int)((context->count[0] >> 3) & 0x3f);
  padLen = (index < 56) ? (56 - index) : (120 - index);
  MD5Update (context, PADDING, padLen);

  /* Append length (before padding) */
  MD5Update (context, bits, 8);

  /* Store state in digest */
  Encode (digest, context->state, 16);

  /* Zeroize sensitive information.
   */
  MD5_memset ((POINTER)context, 0, sizeof (*context));

  DEBUG_PRINT(("</MD5Final>\n"));
}

/* MD5 basic transformation. Transforms state based on block.
 */
static void MD5Transform (UINT4 state[4], unsigned char block[64])
{
  UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];

  Decode (x, block, 64);

  /* Round 1 */
  FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
  FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
  FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
  FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
  FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
  FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
  FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
  FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
  FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
  FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
  FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
  FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
  FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
  FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
  FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
  FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */

  /* Round 2 */
  GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
  GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
  GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
  GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
  GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
  GG (d, a, b, c, x[10], S22,  0x2441453); /* 22 */
  GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
  GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
  GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
  GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
  GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */

  GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
  GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
  GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
  GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
  GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */

  /* Round 3 */
  HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
  HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
  HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
  HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
  HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
  HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
  HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
  HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
  HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
  HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
  HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
  HH (b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
  HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
  HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
  HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
  HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */

  /* Round 4 */
  II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
  II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
  II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
  II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
  II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
  II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
  II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
  II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
  II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
  II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
  II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
  II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
  II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
  II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
  II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
  II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */

  state[0] += a;
  state[1] += b;
  state[2] += c;
  state[3] += d;

 
  /* Zeroize sensitive information.

   */
  MD5_memset ((POINTER)x, 0, sizeof (x));

}

/* Encodes input (UINT4) into output (unsigned char). Assumes len is
   a multiple of 4.
*/
static void Encode (unsigned char *output,
		    UINT4 *input, 
		    unsigned int len)
{
  unsigned int i, j;

  for (i = 0, j = 0; j < len; i++, j += 4) {
    output[j] = (unsigned char)(input[i] & 0xff);
    output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
    output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
    output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
  }
}

/* Decodes input (unsigned char) into output (UINT4). Assumes len is
   a multiple of 4.
*/
static void Decode (UINT4 *output, unsigned char *input, unsigned int len)
{
  unsigned int i, j;
  for (i = 0, j = 0; j < len; i++, j += 4)
    output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
      (((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
}

/* Note: Replace "for loop" with standard memcpy if possible.
 */

static void MD5_memcpy (POINTER output,
			POINTER input,
			unsigned int len)
{
  unsigned int i;

  for (i = 0; i < len; i++)

    output[i] = input[i];
}

/* Note: Replace "for loop" with standard memset if possible.
 */
static void MD5_memset (
			POINTER output,
			int value,
			unsigned int len)
{
  unsigned int i;

  for (i = 0; i < len; i++)
    ((char *)output)[i] = (char)value;
}


__device__ void cuda_MD5_String (unsigned char* input, string output)
{
  int len = 0, i = 0;

  while (input[i++] != 0) len++;

  MD5_CTX context;
  MD5Init (&context);
  MD5Update (&context, input, len);
  MD5Final (output, &context);
}

/**
 * kernel a exécuter pour le hash md5
 * @param g_data données reçues pour lesquelles il faut calculer l'empreinte
 * @param g_result empreinte résultante
 * @author fred
 */
__global__ void kernel(unsigned char *g_data, unsigned char *g_result){
  int r = threadIdx.x;
  unsigned char* row = (unsigned char*)((char*)g_data + r*16);
  //printf("==> kernel receives row [%s] %d\n", row, r);
  DEBUG_PRINT(("==> kernel receives row    [%s]\n", row));
  unsigned char* rowout = (unsigned char*)((char*)g_result + r*16);
  cuda_MD5_String(row, rowout);
}


/**
 * driver c pour le kernel a exécuter pour le hash md5
 * @param g_data données reçues pour lesquelles il faut calculer l'empreinte
 * @param g_result empreinte résultante
 * @author fred
 */
extern "C"
{
#include "cuda_inc.h"
  /* driver pour le kernel */
  void cudamd5kernel(unsigned char* g_data, unsigned char* g_result) {
    //cuda_chrono(CHRONO_START);
    kernel <<<1,512>>> (g_data, g_result);
    //cuda_chrono(CHRONO_STOP);
    //cuda_chrono(CHRONO_DISPLAY);
  }
}
